This invention relates to a communication device to be used for a communication network, and more particularly, to a communication device for configuring a link aggregation port to be redundant, which is constructed by using the link aggregation for virtually binding a plurality of physical links to use the plurality of physical links as if the physical links were a single link.
In recent years, the number of forms of providing IT services by using communication networks represented by the cloud service is increasing. For the IT services using the communication networks, a response at the time of using the service and continuity are important, and high speed communication and high reliability are thus required for the communication networks.
As a technology for enhancing a communication bandwidth, the link aggregation is known (refer to Japanese Patent Application Laid-open No. 2008-160227). The link aggregation is a technology for aggregating a plurality of physical ports for coupling between two devices to use the plurality of the physical ports as one link aggregation (LA) logical port.
The link aggregation has such an advantage that a bandwidth of the one logical port is a sum of bandwidths of the aggregated individual links, resulting in an increase in bandwidth. Moreover, the link aggregation also has such an advantage of providing so-called redundancy in a communication path which operates N of the aggregated individual links as active links and operates M of the aggregated individual links as standby links so as to continue the communication on the standby link even when failures occur to some of the active links.
FIG. 2 is an explanatory diagram of the link aggregation, and specifically, illustrates an example where enhancement in communication bandwidth and a redundant configuration of physical links are realized by using six physical ports 204-1 to 204-6 belonging to interface (IF) cards 202-1 between neighboring communication devices 200-1 and 200-2 to build an LA logical port 210 between the communication devices 200-1 and 200-2.
Moreover, as the technology for configuring the physical link to be redundant, there is an Ethernet protection switching function (refer to ITU-T G.8031/Y.1342 Ethernet linear Protection Switching). The Ethernet protection switching uses the automatic protection switching (APS) protocol to configure two physical links to be redundant, and switches a communication path to a physical link in a standby system when a failure occurs on a physical link in the active system. This technology is hereinafter referred to as Ethernet APS.
FIG. 3 is an explanatory diagram of the Ethernet protection switching, and specifically, illustrates an example where redundancy is realized between physical links 304-1 and 304-2 belonging to IF cards 302-1 and 302-2 of neighboring communication devices 300-1 and 300-2 by using the Ethernet APS.